通过whois命令查询域名注册者信息
第一步：whois “＝待查询的域名”
第二步：从上面的输出信息中找到Domain Name下面的whois server名字。
第三步：输入whois -h whois server 待查询域名。
下面以百度为例：

第一步：whois "=baidu.com"

输出
Whois Server Version 2.0

Domain names in the .com and .net domains can now be registered
with many different competing registrars. Go to http://www.internic.net
for detailed information.

Server Name: BAIDU.COM.ZZZZZZ.COM.MORE.INFO.AT.WWW.BEYONDWHOIS.COM
IP Address: 203.36.226.2
Registrar: TUCOWS INC.
Whois Server: whois.tucows.com
Referral URL: http://domainhelp.opensrs.net

Server Name: BAIDU.COM.ZZZZZ.GET.LAID.AT.WWW.SWINGINGCOMMUNITY.COM
IP Address: 69.41.185.203
Registrar: INNERWISE, INC. D/B/A ITSYOURDOMAIN.COM
Whois Server: whois.itsyourdomain.com
Referral URL: http://www.itsyourdomain.com

Server Name: BAIDU.COM.MORE.INFO.AT.WWW.BEYONDWHOIS.COM
IP Address: 203.36.226.2
Registrar: TUCOWS INC.
Whois Server: whois.tucows.com
Referral URL: http://domainhelp.opensrs.net

Domain Name: BAIDU.COM
Registrar: REGISTER.COM, INC.
Whois Server: whois.register.com
Referral URL: http://www.register.com
Name Server: DNS.BAIDU.COM
Name Server: NS2.BAIDU.COM
Name Server: NS3.BAIDU.COM
Name Server: NS4.BAIDU.COM
Status: clientTransferProhibited
Updated Date: 04-sep-2007
Creation Date: 11-oct-1999
Expiration Date: 11-oct-2014

第三步：whois -h whois.register.com baidu.com

之后可以得到需要了解的结果。